1/*
2 * drivers/mtd/maps/ixp2000.c
3 *
4 * Mapping for the Intel XScale IXP2000 based systems
5 *
6 * Copyright (C) 2002 Intel Corp.
7 * Copyright (C) 2003-2004 MontaVista Software, Inc.
8 *
9 * Original Author: Naeem M Afzal <naeem.m.afzal@intel.com>
10 * Maintainer: Deepak Saxena <dsaxena@plexity.net>
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License version 2 as
14 * published by the Free Software Foundation.
15 *
16 */
17
18#include <linux/module.h>
19#include <linux/types.h>
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/string.h>
23#include <linux/slab.h>
24#include <linux/ioport.h>
25#include <linux/device.h>
26#include <linux/platform_device.h>
27
28#include <linux/mtd/mtd.h>
29#include <linux/mtd/map.h>
30#include <linux/mtd/partitions.h>
31
32#include <asm/io.h>
33#include <mach/hardware.h>
34#include <asm/mach/flash.h>
35
36#include <linux/reboot.h>
37
38struct ixp2000_flash_info {
39	struct		mtd_info *mtd;
40	struct		map_info map;
41	struct		resource *res;
42};
43
44static inline unsigned long flash_bank_setup(struct map_info *map, unsigned long ofs)
45{
46	unsigned long (*set_bank)(unsigned long) =
47		(unsigned long(*)(unsigned long))map->map_priv_2;
48
49	return (set_bank ? set_bank(ofs) : ofs);
50}
51
52#ifdef __ARMEB__
53/*
54 * Rev A0 and A1 of IXP2400 silicon have a broken addressing unit which
55 * causes the lower address bits to be XORed with 0x11 on 8 bit accesses
56 * and XORed with 0x10 on 16 bit accesses. See the spec update, erratum 44.
57 */
58static int erratum44_workaround = 0;
59
60static inline unsigned long address_fix8_write(unsigned long addr)
61{
62	if (erratum44_workaround) {
63		return (addr ^ 3);
64	}
65	return addr;
66}
67#else
68
69#define address_fix8_write(x)	(x)
70#endif
71
72static map_word ixp2000_flash_read8(struct map_info *map, unsigned long ofs)
73{
74	map_word val;
75
76	val.x[0] =  *((u8 *)(map->map_priv_1 + flash_bank_setup(map, ofs)));
77	return val;
78}
79
80/*
81 * We can't use the standard memcpy due to the broken SlowPort
82 * address translation on rev A0 and A1 silicon and the fact that
83 * we have banked flash.
84 */
85static void ixp2000_flash_copy_from(struct map_info *map, void *to,
86			      unsigned long from, ssize_t len)
87{
88	from = flash_bank_setup(map, from);
89	while(len--)
90		*(__u8 *) to++ = *(__u8 *)(map->map_priv_1 + from++);
91}
92
93static void ixp2000_flash_write8(struct map_info *map, map_word d, unsigned long ofs)
94{
95	*(__u8 *) (address_fix8_write(map->map_priv_1 +
96				      flash_bank_setup(map, ofs))) = d.x[0];
97}
98
99static void ixp2000_flash_copy_to(struct map_info *map, unsigned long to,
100			    const void *from, ssize_t len)
101{
102	to = flash_bank_setup(map, to);
103	while(len--) {
104		unsigned long tmp = address_fix8_write(map->map_priv_1 + to++);
105		*(__u8 *)(tmp) = *(__u8 *)(from++);
106	}
107}
108
109
110static int ixp2000_flash_remove(struct platform_device *dev)
111{
112	struct flash_platform_data *plat = dev->dev.platform_data;
113	struct ixp2000_flash_info *info = platform_get_drvdata(dev);
114
115	platform_set_drvdata(dev, NULL);
116
117	if(!info)
118		return 0;
119
120	if (info->mtd) {
121		mtd_device_unregister(info->mtd);
122		map_destroy(info->mtd);
123	}
124	if (info->map.map_priv_1)
125		iounmap((void *) info->map.map_priv_1);
126
127	if (info->res) {
128		release_resource(info->res);
129		kfree(info->res);
130	}
131
132	if (plat->exit)
133		plat->exit();
134
135	return 0;
136}
137
138
139static int ixp2000_flash_probe(struct platform_device *dev)
140{
141	static const char *probes[] = { "RedBoot", "cmdlinepart", NULL };
142	struct ixp2000_flash_data *ixp_data = dev->dev.platform_data;
143	struct flash_platform_data *plat;
144	struct ixp2000_flash_info *info;
145	unsigned long window_size;
146	int err = -1;
147
148	if (!ixp_data)
149		return -ENODEV;
150
151	plat = ixp_data->platform_data;
152	if (!plat)
153		return -ENODEV;
154
155	window_size = resource_size(dev->resource);
156	dev_info(&dev->dev, "Probe of IXP2000 flash(%d banks x %dMiB)\n",
157		 ixp_data->nr_banks, ((u32)window_size >> 20));
158
159	if (plat->width != 1) {
160		dev_err(&dev->dev, "IXP2000 MTD map only supports 8-bit mode, asking for %d\n",
161			plat->width * 8);
162		return -EIO;
163	}
164
165	info = kzalloc(sizeof(struct ixp2000_flash_info), GFP_KERNEL);
166	if(!info) {
167		err = -ENOMEM;
168		goto Error;
169	}
170
171	platform_set_drvdata(dev, info);
172
173	/*
174	 * Tell the MTD layer we're not 1:1 mapped so that it does
175	 * not attempt to do a direct access on us.
176	 */
177	info->map.phys = NO_XIP;
178
179	info->map.size = ixp_data->nr_banks * window_size;
180	info->map.bankwidth = 1;
181
182	/*
183 	 * map_priv_2 is used to store a ptr to the bank_setup routine
184 	 */
185	info->map.map_priv_2 = (unsigned long) ixp_data->bank_setup;
186
187	info->map.name = dev_name(&dev->dev);
188	info->map.read = ixp2000_flash_read8;
189	info->map.write = ixp2000_flash_write8;
190	info->map.copy_from = ixp2000_flash_copy_from;
191	info->map.copy_to = ixp2000_flash_copy_to;
192
193	info->res = request_mem_region(dev->resource->start,
194				       resource_size(dev->resource),
195				       dev_name(&dev->dev));
196	if (!info->res) {
197		dev_err(&dev->dev, "Could not reserve memory region\n");
198		err = -ENOMEM;
199		goto Error;
200	}
201
202	info->map.map_priv_1 =
203		(unsigned long)ioremap(dev->resource->start,
204				       resource_size(dev->resource));
205	if (!info->map.map_priv_1) {
206		dev_err(&dev->dev, "Failed to ioremap flash region\n");
207		err = -EIO;
208		goto Error;
209	}
210
211#if defined(__ARMEB__)
212	/*
213	 * Enable erratum 44 workaround for NPUs with broken slowport
214	 */
215
216	erratum44_workaround = ixp2000_has_broken_slowport();
217	dev_info(&dev->dev, "Erratum 44 workaround %s\n",
218	       erratum44_workaround ? "enabled" : "disabled");
219#endif
220
221	info->mtd = do_map_probe(plat->map_name, &info->map);
222	if (!info->mtd) {
223		dev_err(&dev->dev, "map_probe failed\n");
224		err = -ENXIO;
225		goto Error;
226	}
227	info->mtd->owner = THIS_MODULE;
228
229	err = mtd_device_parse_register(info->mtd, probes, NULL, NULL, 0);
230	if (err)
231		goto Error;
232
233	return 0;
234
235Error:
236	ixp2000_flash_remove(dev);
237	return err;
238}
239
240static struct platform_driver ixp2000_flash_driver = {
241	.probe		= ixp2000_flash_probe,
242	.remove		= ixp2000_flash_remove,
243	.driver		= {
244		.name	= "IXP2000-Flash",
245		.owner	= THIS_MODULE,
246	},
247};
248
249module_platform_driver(ixp2000_flash_driver);
250
251MODULE_LICENSE("GPL");
252MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net>");
253MODULE_ALIAS("platform:IXP2000-Flash");
254